Unlike the Sony PVM series, the XM29 Plus has no support for component inputs, but it supports almost everything else (Svideo, composite, RGBHV, VGA). You can get a YPbPr-to-VGA transcoder, like this thing, but most of them (including that one) don't support resolutions below 640x480, so they're not good for PS1 (which frequently jumps between 480i and "240p"), non-progressive PS2 games (admittedly, the vast majority of PS2 games are 480p-capable), or "240p"/doublestrike emulation via Wii homebrew, etc.
That said, I don't think component is a particularly useful on the XM29, which is a shame because that's what I had settled on for use with my PVM. Instead, it seems best to stick with RGB SCART, which is easily converted to RGBHV, as the XM29 has two of those inputs available. You will need a sync cleaner, though, so either get a sync strike or get a cable with a sync cleaner built-in, like this one.
There's a lot of uncertainty online about which resolutions work over SCART but I can answer definitively: 480p over RGB SCART totally works fine.
Other than that, there's not much else to say. Low-res non-interlaced content has extremely sharp scanlines with thick, black spaces between them, which some people don't care for. Likewise, interlaced content bobs very visibly when sitting close to the screen. Slight geometry issues are also apparently common on these monitors, and mine's no exception. However, it still looks great and many of the imperfections can be hidden with a teensy bit of overscan.
Here are some shots (click to embiggen):
|240 noninterlaced full frame TATE|
|240 noninterlaced closeup TATE|